function abreVentana(URL,WIDTH,HEIGHT){
	windowprops= "left=280,top=100,width=" + WIDTH + ",height=" + HEIGHT;
	preview= window.open(URL,"preview",windowprops);
	}
if (navigator.appName == "Netscape") 
		{								
		cssfile = "ns4.css";
		
		}
	else 	
		cssfile = "ie4.css";					
estilos = "<link rel=\"stylesheet\" href=\"/css/" + cssfile +"\">";
document.write(estilos);